The invention relates to a fire-control apparatus for anti-aircraft defense systems, particularly mobile ones, of the generic type including: a platform that rotates around a vertical axis; at least one launch apparatus for guided missiles provided with homing heads, which apparatus is pivotable around a horizontal axis and is disposed on the platform; at least one optical target-tracking sensor, which continuously determines target data, such as position, velocity and range, rigidly coupled with the launch apparatuses; a directional angle computer that is connected to the target-tracking sensor and, from the target data, calculates the estimated point of impact of a guided missile and an airborne target and the directional angles "lead" and "elevation" necessary for the launch of the guided missile; a follow-up computer that is connected to the target-tracking sensor and generates follow-up signals in azimuth and elevation from the deviations of the target position from the line of sight of the target-tracking sensor; and a control unit, which is connected to the follow-up directional angle computers and has adjustment drives for the platform and the launch apparatus, which pivots the platform in azimuth and the launch apparatuses in elevation as a function of the follow-up signals and, prior to launch, locks the lead on the platform and the elevation on the launch apparatus.
In a known fire-control apparatus for an anti-aircraft tank with cannon (CH 665,493.A5), the target-tracking sensor includes a tracking radar, which automatically tracks the target, and supplies continuously measured data, such as target position, velocity and acceleration, as well as a laser range finder, which supplies a redundant, interference-immune measurement of target distance. The target data of the tracking radar and of the laser range finder are transmitted to the directional angle computer, which utilizes them to determine the directional angles for lead and elevation for the turret and weapon, taking into consideration everyday conditions such as initial projectile velocity, air pressure, temperature, wind intensity and wind direction.
The tracking radar, the laser range finder and the weapon are autonomous systems connected with one another by means of follow-up computers.
In a known fire-control apparatus of the above-mentioned type for anti-aircraft systems equipped with guided missiles, such as Stingers, Mistrals or the like, optical sensors such as a TV camera and/or an infrared camera connected to a laser range finder are used as target-tracking sensors. Because guided missiles have their own homing head, which typically operates on an infrared basis, for structural simplification the target-tracking sensor is rigidly coupled with the launch apparatus for the guided missiles, which is pivotable in elevation, and the two are disposed together on a platform that is rotatable in azimuth. In this way, the line of sight of the target-tracking sensor and the longitudinal axis of the launch apparatus for the guided missiles are always oriented nearly parallel to one another, so that the control unit need only adjust the platform in azimuth and the launch apparatus in elevation corresponding to the follow-up signals generated by the follow-up computer in order to pan the target-tracking sensor. During tracking the line of sight of the homing head of the guided missile is aligned with the axis of the launch apparatus and thus, like the line of sight of the target-tracking sensor, oriented toward the target. Before the missile is launched, target lock-on is effected by the stabilized homing head of the guided missile, following which the platform is pivoted by the lead in azimuth, and the launch apparatus is pivoted in elevation by the tangential sight. The consequence of this is that the homing head of the guided missile tracks the target, but the lines of sight of the target-tracking sensor and the guided missile themselves are pivoted by the directional angles and are oriented toward the calculated point of impact, the so-called "kill point," and therefore no longer toward the target. The resulting loss of target by the target-tracking sensor has the drawback that, to execute a second launch toward the same target with a second launch apparatus that is rigidly coupled with the first launch apparatus and always takes part in its adjustment motion, the target must be reacquired, then transmitted to the target-tracking sensor. In many cases, the required, not insignificant, time span until the second launch occurs reduces the fighting power of the anti-aircraft defense system. The same problem occurs when, after the first projectile has been launched, a second target is to be attacked that is flying close to the tracked target and is therefore in the visual field of the target-tracking sensor. The consequence of the loss of the target by the target-tracking sensor during launch of the guided missile is that the second target is also lost, and must be subsequently reacquired.
It is an object of the invention to improve a fire-control apparatus of the type described at the outset such that, during target lock-on prior to launch, and the associated adjustment of the launch apparatus by the required directional angle in azimuth and elevation, the target-tracking sensor remains in contact with the target.